Many oligosaccharides are commonly prepared by the control hydrolytic cleavage of starches. In the production of oligosaccharides, the glycosidic linkages of the starch molecules are partially hydrolyzed to yield at least one oligosaccharide species, and more typically, a mixture of oligosaccharide species. The oligosaccharide mixtures so prepared typically include at least one malto-oligosaccharide species. Malto-oligosaccharides are characterized as having a saccharide backbone that comprises predominantly 1-4 glycosidic linkages.
Malto-oligosaccharides may be characterized by their degree of polymerization (DP) which refers to the number of saccharide monomer units in each molecule. Each malto-oligosaccharide species also may be characterized by its dextrose equivalent value (DE) which is a measure of the reducing power of the malto-oligosaccharide relative to dextrose and which may be determined by the Lane and Eynon method or the Luff-Schoorl method as known in the art. Conventional malto-oligosaccharides generally are divided into maltodextrins and syrup solids. Malto-oligosaccharides having a DE of less than 20 are known as maltodextrins, whereas malto-oligosaccharides having a DE of 20 or greater are known as syrup solids.
Malto-oligosaccharides generally may be prepared via the corn wet milling process. In the corn wet milling process, corn is soaked in sulfur dioxide (SO2) for a typical period of roughly 24-36 hours. This causes the corn kernel to separate into its four main component parts, which are germ, protein, fiber, and starch. The starch is then recovered and, when used for the production of malto-oligosaccharides, is subjected to enzymatically catalyzed hydrolysis to yield a mixture malto-oligosaccharides. The other component parts of the corn are used as feed or are themselves further processed to yield other commercially valuable products. The corn wet milling process is commercially practiced at present by Grain Processing Corporation of Muscatine, Iowa. Grain Processing Corporation is a commercial supplier of many food-grade malto-oligosaccharides sold under the MALTRIN® trademark. MALTRIN® malto-ologosaccharides are filtered, carbon-treated, and spray-dried products. The commercially available MALTRIN® product line covers a range of DE values from 5-25. Exemplary MALTRIN® products include MALTRIN® M040; MALTRIN® M100; MALTRIN® M150; MALTRIN® M180, and MALTRIN® QD grades M500, M510, M550, and M580.
The corn wet milling process, while well established, makes use of a substantial amount of sulfur dioxide. For some purposes it would be desirable to provide a method for production of malto-oligosaccharides that is capable of practice using less sulfur dioxide.